Advice needed

Me and my bf recently broke up due to stress and personal issues. I respect this and im working over it. The problem is I haven't been single in over a year and 6 months, and im not sure what to do with all this free time. Im 16 so I've caught up on hw, but when I get done with that, then what? Im trying to open up and enjoy this time to myslef. We've talked about it and decided to remain single until summer break and then get back together, so I have 3 months to kill. Any ideas of what I should do?